<template>
  <div class="login_container">
    <div class="login_box">
      <span id="loginSpan" :style="{opacity}">LOGIN</span>
      <!-- 登录表单区 -->
      <!-- rules为表单验证规则 -->
      <el-form
        ref="loginFormRef"
        :model="loginForm"
        :rules="loginFormRules"
        class="login_form"
      >
        <!-- 用户名 -->
        <el-form-item prop="username">
          <el-input
            v-model="loginForm.username"
            prefix-icon="el-icon-user-solid"
          ></el-input>
        </el-form-item>
        <!-- 密码 -->
        <el-form-item prop="password">
          <el-input
            v-model="loginForm.password"
            type="password"
            prefix-icon="el-icon-lock"
          ></el-input>
        </el-form-item>
        <!-- 按钮区域 -->
        <el-form-item class="btns">
          <el-button type="primary" @click="login">登录</el-button>
          <el-button type="info" @click="resetLoginForm">重置</el-button>
        </el-form-item>
      </el-form>
    </div>
  </div>
</template>

<script>
export default {
  data() {
    return {
      // 登陆表单的数据绑定对象
      opacity:0.1,
      loginForm: {
        username: 'admin',
        password: '123456',
      },
      // 表单验证规则对象
      loginFormRules: {
        // 验证用户名
        username: [
          { required: true, message: '请输入登录名称', trigger: 'blur' },
          {
            min: 3,
            max: 10,
            message: '长度在 3 到 10 个字符',
            trigger: 'blur',
          },
        ],
        // 验证密码
        password: [
          { required: true, message: '请输入登录密码', trigger: 'blur' },
          {
            min: 6,
            max: 15,
            message: '长度在 6 到 15 个字符',
            trigger: 'blur',
          },
        ],
      },
    }
  },
  methods: {
    //   点击重置按钮，重置登录表单
    resetLoginForm() {
      this.$refs.loginFormRef.resetFields()
    },
    login() {
      this.$refs.loginFormRef.validate(async (valid) => {
        if (!valid) return //如果返回值为false则直接返回不去发送请求
        //  发送登录请求
        const { data: res } = await this.$http.post('login', this.loginForm)
        if (res.meta.status !== 200) return this.$message.error('登录失败')
        this.$message.success('登录成功')
        //  1、将登录成功之后的token，保存到客户端的sessionStorage中
        window.sessionStorage.setItem('token', res.data.token)

        this.$router.push('/home')
      })
    },
    
  },
  mounted(){
    this.timer=setInterval(() => {
              this.opacity -= 0.01;	//this指向的是vue实例对象
              if (this.opacity <= 0) this.opacity = 1;
          }, 20)
  },
  beforeDestroy(){
    clearInterval(this.timer);
  }
}
</script>

<style lang="less" scoped>
.login_container {
  background: rgb(107, 181, 224) linear-gradient(to right, rgba(0,255,0,0), rgba(147, 219, 180, 1));
	transition: background-color .5s;
  height: 100%;
}
.login_box {
  width: 450px;
  height: 300px;
  background-color: rgba(255, 255, 255, .3);
  border-radius: 3px;
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  text-align: center;
  #loginSpan{
    font-size: 60px;
    color: #fff;
    display: block;
    margin-top: 15px;
  }
}
.login_form {
  position: absolute;
  bottom: 0;
  width: 100%;
  padding: 0 20px;
  box-sizing: border-box;
}
.btns {
  display: flex;
  justify-content: flex-end;
}
</style>